Interlocking system for railroads



Nov. 29, 1932. J. E. STEPHENSON INTERLOCKING SYSTEM FOR RAILROADS Filed Sept. 4. 1930 INVENTO 2. WW BY? ZMZZ @622 @ATTQRNEY Patented Nov. 2 9 1932 UNITED STATES PATENT OFFICE i JAMES E. srErHENsomoE ROCHESTER, NEW YORK, ASSIGNOR- T GENERAL RAILWAY SIGNAL COMPANY, on nocnEsrEE, N W roan 8 INTER-LOCKING SYSiTEM. FQR RAILROADS Application filed September 4, 1930. Seral No. 479,668.

This invention relates to electric interlocking systems for railroads and more particularly to a dual control system for a traific controlling device of such a system.

In an electric interlocking system, it is sometimes desirable that a trainman or other authorized person be able to operate certain switches locally without the aid of the towerman. It is also faster and more convenient to enable the switchman to operate the switch electrically, by the switch machine, than by an auxiliary hand throw device. In such an operation it is necessary to deprive the tower mechanism of the control of this switch machine while operating it locally, and also necessary for safe operation that the signals associated with the route governed by this switch'machine restrict the movement of other trains during'such operation.

With the above and other considerations in mind, it is proposed in accordance with the present invention to provide in combination with the usual tower control lever and a switch machine, a field circuit controller by which the switch machine can be controlled irrespective of the tower control lever but employing the same tower operating energy.

It is also proposed to provide ameans for locking the tower control lever whenthe control of'the switch machine is withthe field circuit controller, and to indicate to the tower operator when such a condition exists.

Other objects, purposes and characteristic features of the invention will appear as the description of the invention progress-es.

In describing theinvention in detail, reference will be made to the accompanying drawing, which consists of a single figure showing diagrammatically an application of the present invention to obtain the dual electric control of a switch machine. In illustrating the invention, the various parts have been shown in a manner to make it easyto understand the invention, rather than. with the view of showingthe particular construction preferably employed in practice.

Referring to the accompanying drawing, a track switch TS is shown leading from a track T and controlled by a switch machine SM. The operation of the switch machine SM is controlled fromthe tower in the usual which does not depend on dynamic snubbing and is provided with three wire control may.

be controlled according to this invention, and as the construction of such a switch machine is well known, only those parts directly involved in making a clear explanation of the I present invention are shown.

These parts of the switch machine are shown within a'dotted rectangle landinclude the operating motor shown conveniently as including a field F, an armature A with a brake BR, and a plurality of stationary contacts 2, 3, 4 and. 5 and movable contact blocks 6 and 7 as shown. The stationary contacts 2, 3, 4 and 5 are arranged to polechange the armature A with respect tov the field F by the shifting otthe contact blocks 6 and 7 at the completion of a stroke of the switch machine. i I Enclosed in the dotted rectangle D "is shown a typical point detector contact arrangement the operation of which can be clearly understood from the patent to (LS. Bushnell No. 1,517,286 dated November 25,

1925. This arrangement shows four pairs of stationary contact fingers 42,43, and 61 which arealternately engaged in the manner shown by contact blocks 40 and 41 when in positions corresponding to the extreme posltions of the switch TS. Associated with these contacts and operated by the contact blocks 40 and 41 are two movable contact arms50 and 44 which are'allowed toengage station- 'ary contacts 49 and 45 respectively in the mid position of the switch TS by the disengagement of tips 40 and 41 from the contact extensions 50 and 44 respectively. The

contact block 40in one extreme position disengages contacts 50 and 49 by the engagement of tip 40 and contact extension 50 and likewise contact-block 41 in the other extreme position disengages contacts 44 and 45 by the engagement of tip 41 and contactextension 44 Any suitable pole changer contact arrangement which is operated by the 1 movement of the switch, can be used however in this circuit, as well as the arrangement shown, and it is desired to be understood that the present invention is not limited to the use of the particular point detector arrangement illustrated.

The control lever L in the interlocking machine is of well known construction and the principal parts of interest in connection way as toblo'ck its movement into either ex treme position when the solenoid is deenergized. The operating handle of lever L has a latch 20 arranged to block accidental movement, and when unlatched is arranged to close a break in the energizing circuit of the electric lock EL by raising plunger 21 which inovescontact arm 17 against stationary contact 18. The lever L, being a part of an interlocking system, is mechanically interlocked with other conflicting levers by a tappet bar 22 operated by a roller 23 moving in a slot 24. r

The local controller for the switch machine is diagrammatically shown in the enclosed rectangle C and consists primarily of a plurality of insulated contact fingers 31, 80, 69, 29, 55, 52, and 67 operable in unison to any one of the three indicated positions, ofi, normal or reverse, by a manually operable control arm 25.

In addition to the above mentioned apparatus, the system includes an indication lamp IL associated with the tower control lever L and controlled from the field controller C so as to be energized when the fieldcontroller is in either of the switch controlling positions. The tower apparatus also includes a polarized signal control relay lVP which ordinarily operates in accordance with the movement of the switch machine SM and the control circuit of which is more fully described hereinafter. A detector track section T extends a predetermined distance in each direction from the track switch TS and is separated from the adjacent sections by insulated rail joints I. A suitable track battery TBis connected across the rails at one end of the section and under norfnal conditions energizes a track relay TR connected across the rails at the other end of the track section. In order to obtain a clear understanding of the present invention, it is necessary to consider' the operation of the switch machine from each of the control points. It will first be assumed that the detector track section T is unoccupied and relay TB is energized, and that the tower operator desires to operate the switch machine SM from its normal position, (as shown) to its reverse position. If

the conflicting levers are'in theirproper positions so that lever L is not mechanically locked by tappet 22, the latch 20 may be re.- leased which action'closesthe electric lock energizing contacts 17 and 18 thus raising the locking dog 19 which releases the lever L and allows it to be pulled back to its reverse position. c

This movement of the lever L moves the contactblocks 1O and'll out of engagement with contacts 13 and contacts 15 and into engagement with contacts 12 and contacts 14. This closes the operating circuit for the switch machine SM as follows :beginning at the operating battery B, wires 26 and 27, contacts 14 bridged byv contact block 11, wire 28, reverse control wire R, field controller contact 29 in the ofi'position to wire 30,

field controller 'c ontact'31, field reverse control wire R pole changer contacts 2 bridged by contact block 6, wires 32 and 33, armature-A, wire 34, contacts 3 bridged by contact block 7, wires 35 and 36, field'winding F, wire 37, brake winding 38 of armature brake BR, common return wire COM, wire 39 back to'the other terminal of battery'B.

The completion-oft this circuit just traced causes the switch machine SMto operate the track switch TS to its reverse position, and

upon reaching the reverse position the contact blocks 6 and 7 of the pole changer are shifted to a position bridging the contacts 4 and contacts 5. Thisinterrupts the operating circuit of the motor and applies the armature brake BR by deenergizingthe retaining magnet 88, and also prepares the circuit for the next operation upon" the movement of lever L back to its normal position."

The control circuit for the relay WP when the switch machine SM is in the normal position as shown on the diagram, or theposition which it assumed before the above operation, may be traced as follows :'beginning at the positive terminal of the field source of energy E, wires 46 and 47, point detector contacts 42 bridged by contact block 40, wire 48, stationary contact 49, contact 50, wire 5 1,'field controller contact 52in the off position,

wire 53, winding of relay WP, wire 5e, field controller contact 55, wire 56, point detector contacts 43 bridged by contact block 41, wire 57, Wire 58 'back to negative terminal of the source of energy E." This causes a current to flow through the windings of the relay WP in a definite direction which causes the armature 59 to assume a position at n as shown.

During the operation of the switch machine the contact blocks 40 and 41 are moved clear of the contacts 42 and contacts 13 and coni tact 44 is allowed to close on contact 45 by the disengagement of tips 41 and 44 This shunts the winding of relay WVP through wire 53, contact52 of the field controller C, wire 51, contacts and 49, wires 62 and 63, contacts 44 and 45, wires 64 and 56, contact 55 of the field controller C, wire 54 to the windings of relay WP. This causes the relay armature 59 to assume the deen'ergized position (Z.

When the switch machine has completed the reverse movement the contact blocks 40 and 41 bridge contacts 60 and 61 and contact 50 is disengaged from'contact 49 by the engagement of tips 40 and 50 This places 'a current of a relatively reverse polarity'on the windings of relay WPover the following circuit :-beginning at the positive terminal of the field source of energy E, wire-46, contacts 61 bridged by contact block 41, wires,

65 and 63, contact 44, contact 45, wires 64 and 56, contact 55 of field controller C in the ofi position, wire 54, winding of relay WP, wire 53, contact 52 of the field controller C, wires 51 and 66 contacts 60 bridged by contact block 40, wire 58, back to negative of the local source of energy E. This circuit supplies a current which flows through the relay windlngs in a relatively opposite direction to that when the switch was in its normal position.

This causes the armature of the polarized relay WP to assume an opposite extreme posi-- tion 1'.

The normal operating circuit'of the switch machine is similar to the reverse operating circuit previously traced and can be readily understood from the drawing. The point detector contacts will likewise operate through a'cycle which is simply converse to the one just described, and by reasonof their similarity it is not considered necessary to trace these circuits. 1

It is now assumed that itis'desired to oper ate the switch machine SM by its field controller C to its reverse position while the tower controller of lever L is in the normal position as shown. 7 Inasmuch as'the operator of the field controllerC is inposition to know the conditions of the track T adjacent the switch TS, it is not considered necessary for the field controller C to be electrically'loc-ked by the detector track circuit, and consequently the operator is able to move the control arm 25 from its inactive or off position to its normal position andthen to itsreverse by a previous operation of the switch ma-' chine. V

The field controller when in either the normal positionor'the"reverse position.

prevents the'operation' of thetower lever L by opening the energizing circuit of the electrio lock 'EL at its contact-'67. "The indicationlamp IL is also energized when the field controller is in either of the'above mentioned active positions over the following circuit beginning at battery B, wires 26 and 68, contacts 15 bridged by contact block 11, normal control wire N, field controller contact 69 which is connected tofield controller 29'by wires 72 and 73, reverse control wire R, contion, wires 72 and 77, field controller contact 31, field reverse control wire R contacts 2 bridged by contactblock 6, wires 32 and 33, armature A, wire 34, contacts 3 bridged by contact block 7, wires 35 and 36, field winding F, wire 37, winding 38 of armature brake BR, .commonreturn-wire COM, wire 39 back to the opposite terminal of battery B.

The circuit thus completed will cause'the same switch operation as the reverse operation which was previously described, except that the point detector circuit is broken through the field controller contacts 52 and 55 in either the normal or the reverse position, and as an added precaution the windings of relay WP are shunted by wire 79. This assures that'the armature of relay WP assumes its deenergized position d.

The field controller C may again be operated to its normal position where it completes a similar circuit to operate the'switch to its normal position. It is noted from the drawing that the operation ofthe field controller C is independent of the position of the tower control lever L inasmuch as "the control wires N and R are shunted byjthefield controller contacts 69 -and;29,'in an active position, which takes energy fro'rn'whichever control wire is energized by the tower control lever L and applies it to either of the field control wires N or R through-either contact or 31 according to the field controller position. v

By operating the field controller C back and forth between the normal and reverse positions, the switch machine SM may be operated to the corresponding positions at the-will-of the local operator, butin either position, the towerindicator lamp IL is'energized, the tower controllever L is electrically locked, and any associated signals give a restrictive indication, all of which is in accordance withsafe switchoperation. When the field operator has completed his" opera tions, the "field controller should again be returned to the off position, whereby the con trol from the tower will again be established, and the'switch machine will assume a'posie tion corresponding to the position of the tower controller. l

Having thus shown and described one specific embodiment of the present invention, and having shown it applied to a single circuit arrangement, it is desired to be understood that this has been done for the purpose of showing how the invention maybe applied rather than illustrating its scope or the exact construction preferably employedin practice; and that the specific arrangement shown is susceptible of considerable modifications to adapt the invention to the particular inter-- locking system to which the invention is applied, all without departing fromithe scope of the invention or the idea of means underlying the same.

Having thus described my invention, what I claim is: I r j.

1. In a power operated interlocking system, the combination with a central source of energy, a power operated switch machine, a tower control lever for said switch machine. control wires for said switch machine, a field source of energy at said switch machine, a tower signal control means, indication wires for said switch machine, means at said switch machine for applyingthe field sourceof energy to said signal control means to repeat the operation of the switch machine of a manually operable field controller for said switch ma chine, said field controller being adapted to operate the switch machine by energy from said central source of energy, said field controller being operable to either of two switch controlling positions or a neutral position.

2. In an electric interlocking system the combination with a central source of energy, a power operated switch machine, a tower control lever for said switch machine, of a field manually operable controller for said switch machine, said field controller being operable to either of two control positions or a neutral position, said field' controller when in a control position opening the operating circuit of said tower controller.

3. In an electric interlocking system, the combination with a centralsource of energy, a power operated switch machine, a tower control lever for said switch machine, a field controller for said switch machine, of an indicator at said tower control lever,said field controller being manually operable to either a normal or a reverse switch operating position from a neutral positoin,said field controller when in either of said operating positions being adapted to energize said indicator at control station. 1

4. In an electric interlocking system, the combination with a central source of energy,

a power .operatedswitch machine,-atower control'lever for said switch. machine, an electro-responsive locking means associated with ;said tower control lever, a detector track circuit arranged to control said locking means, of-a field controller for said switch machine, said field controller being operable to either of two switch controlling positions or a neutral position, said field controller when in either of the controlling positions being adapted to lock said tower control lever by said locking means.

5. In combination, a power operated switch machine; a lever of an interlocking system for controlling said switch machine, a central source of energy, control wires for operating said switch machine, a field source of energy at said switch machine, indication wires for said switch machine, means for applying said field energy. to said indication wires at. a polarity determined by the position of said switch machine, a tower signal control means responsive to said field energy from said indication wires, and a field controller for said switch machine, said field controllerbeing manually operable to either of two switch operating positions or a neutral position, said field controller when in either switch controlling positions being adapted to disconnect said field source of energy from said indication wires and to shunt said tower signal control means over the indication wires.

6. In an interlocking system, in combination with a central source of energy, a trafiic controlling device and a control lever of an interlocking system, c a manually operable local controller to operate the traffic controlling device by the central source of energy,

saidlocal controller being arranged to deprive the control lever of the interlocking system of its function and to indicate at the'control lever the presence of such a condition.

7 In an interlocking system, a track switch, a motor for moving said switch, operating circuits for the motor, a first and a second controlmeans for said circuits, said first control means being subject to control by said second control means.

8. In a control system for power operating a switch machine from two distinct locations, in combination, a first control means.

having a normal position and a reverse position, a second control means having a neutral position, a normal position and a reverse position, said first control means being inoperable when said second control means is in said normal position or in said reverse position.

9. In an interlocking system, a track switch, a switch machine for moving said track switch, power operating means for said switch machine, a centrally located control means and a local control means each for controlling the power operation of said switch a machine in each of two directions, at will.

10. In an interlocking system; a track switch; a switch machine for said track switch; a control lever in a tower; a source of energy in the tower; control wires for said switch machine extending from the tower; means including said control lever for energizing said control wires to govern the normal and reverse operation of said switch machine; an indication relay in the tower;

- indication wires extending from the tower to the switch machine; means for distinctively energizing said indication wires depending upon the position of said track switch, whereby said indication relay indicates the position I of said track switch; and other control means effective, when operated, for energizing saidcontrol wires for said switch machine independently of the position of said control lever, for rendering saidicontrol lever ineffective, and for preventing said indication relay from being distinctively energized.

11. In an interlocking system forrailroads, a track switch, a switch machine for operating said track switch to normal and reverse positions, normal and reverse operating circuits for sald swltch machlne, a tower control lever for energizing either said normal or sald reverse operating circuit, and a local control lever for energizing either said normal or said reverse operating circuit independently of the position of said tower control lever and for preventing said tower control lever from selectively energizing said operating circuits.

In testimony whereof I aflix my signature.

JAMES E. STEPHENSON. 

